Added main option to bower.json for wiredep support

[jsheffers]

I'm using wiredep to automatically inject bower dependencies into my project and jDrupal doesn't have the "main" option set in bower.json, so wiredep doesn't know which file to inject. This is a quick pull request that links directly to the main minified file.

Reference: https://github.com/taptapship/wiredep#bower-overrides

As stated on the wiredep readme, it's not the only service that relies upon the main option to grab the proper file.

[signalpoint]

@jsheffers Excellent, thank you.